Flush membrane core body, preparation method and application thereof, and pressure transmitter

Abstract

The invention belongs to the technical field of pressure sensors, and particularly relates to a flush membrane core, a preparation method and application thereof, and a pressure transmitter. The flush membrane core body comprises a steel base and a flush membrane; wherein the flush membrane comprises a composite strain layer; the composite strain layer comprises a first strain layer, a second strain layer, a third strain layer and a fourth strain layer which are stacked in sequence, and the first strain layer, the second strain layer, the third strain layer and the fourth strain layer cooperate with one another to sense pressure from all directions, so that the strain sensitivity of the flush membrane core is improved. The pressure transmitter containing the flush membrane core body provided by the invention has very high overload capacity, so that the pressure transmitter can keep stable performance in a severe working environment and provide accurate pressure data.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure sensors, and in particular relates to a flush membrane core body, a preparation method and application thereof, and a pressure transmitter. Background Art

[0002] Flush diaphragm is an essential component in pressure transmitters. Its measuring diaphragm and the contact surface of the measured medium are in the same plane, without protruding or recessed parts. This design enables the diaphragm to directly contact the measured medium, thereby transmitting pressure signals more accurately.

[0003] Although the existing flush membrane has the advantages of wide pressure measurement range, high accuracy, and resistance to electromagnetic interference, it is easily affected by temperature, humidity, mechanical vibration, etc., and has reduced sensitivity and poor stability in high temperature or corrosive environments, resulting in reduced accuracy of measurement results. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a flush membrane core body and a preparation method and application thereof, and a pressure transmitter. The flush membrane core body comprises four strain layers.

[0005] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a flush membrane core, comprising a steel base and a flush membrane; Wherein, the flush membrane comprises a composite strain layer; The composite strain layer comprises a first strain layer, a second strain layer, a third strain layer and a fourth strain layer stacked in sequence; The material of the first strained layer includes SiGeSnN; The material of the second strained layer includes SiGeSnNiN; The material of the third strained layer includes SiGeSnNiCrInN; The material of the fourth strained layer includes SiGeNiCrInGaN.

[0006] In some possible implementations, the material of the first strained layer includes the following elements in atomic percentage: Si: 28%~32%, Ge: 25%~31%, Sn: 30%~35%, N: 5%~10%.

[0007] In some possible implementations, the thickness of the first strained layer is 80 nm to 100 nm.

[0008] In some possible implementations, the material of the second strained layer includes the following elements in atomic percentage: Si: 27%~35%, Ge: 28%~37%, Sn: 18%~25%, Ni: 15%~22%, N: 3%~8%.

[0009] In some possible implementations, the thickness of the second strained layer is 90 nm to 120 nm.

[0010] In some possible implementations, the material of the third strained layer includes the following elements in atomic percentage: Si: 19%~25%, Ge: 21%~28%, Sn: 23%~29%, Ni: 17%~21%, Cr: 8%~14%, In: 3%~8%, N: 1%~2%.

[0011] In some possible implementations, the thickness of the third strained layer is 110 nm to 150 nm.

[0012] In some possible implementations, the material of the fourth strained layer includes the following elements in atomic percentage: Si: 23%~28%, Ge: 13%~25%, Ni: 15%~25%, Cr: 18%~21%, In: 5%~10%, Ga: 5%~10%, N: 2%~5%.

[0013] In some possible implementations, the thickness of the fourth strained layer is 110 nm to 150 nm.

[0014] In some possible implementations, the flush film further includes a transition layer, an insulating layer, a protective layer, and a pad; The steel base, the transition layer, the insulating layer, the composite strain layer and the pad are stacked in sequence longitudinally; The protective layer is arranged on the surfaces of the transition layer, the insulating layer and the composite strain layer.

[0015] In a second aspect, the present invention provides a method for preparing a flush membrane core, comprising the following steps: Prepare a transition layer, an insulating layer and a composite strain layer on the surface of the steel base respectively; fixing a pad on the composite strain layer; The protective layer is formed on the remaining parts of the surfaces of the transition layer, the insulating layer and the composite strained layer.

[0016] In a third aspect, the present invention provides a pressure transmitter, comprising the flush membrane core provided by the present invention.

[0017] In a fourth aspect, the present invention provides an application of the flush membrane core provided by the present invention in the field of strain materials.

[0018] The nano-leveling membrane, preparation method and application thereof, and pressure transmitter provided by the present invention have at least the following beneficial technical effects compared with the prior art: (1) The flush film core provided by the present invention comprises a composite strain layer including four strain layers, wherein Si, Ge and Sn are all metal elements of the IVA group, and In and Ga are adjacent metal elements of the IIIA group. Therefore, the element type difference between the layers is small, so that the bonding strength between two adjacent layers is high, thereby improving the stability of the composite strain layer; the first strain layer, the second strain layer, the third strain layer and the fourth strain layer cooperate with each other to sense pressure from all directions, thereby improving the strain sensitivity of the flush film core.

[0019] (2) In the flush membrane core provided by the present invention, in the composite strain layer, N in each strain layer forms silicon nitride or gallium nitride with metal silicon or gallium. Silicon nitride and gallium nitride have high corrosion resistance, high sensitivity and high stability in high temperature or corrosive environment, etc., so that the measurement results are highly accurate.

[0020] (3) The pressure transmitter with a flush membrane core provided by the present invention has a high overload capacity, which enables it to maintain stable performance in harsh working environments and provide accurate pressure data. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present drawings or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present drawings. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0022] Figure 1 This is a schematic diagram of a cross-sectional structure of a flush membrane core in an embodiment of the present invention; Figure 2 is a schematic diagram of the cross-sectional structure of the composite strain layer in an embodiment of the present invention; Figure 3 is a schematic diagram of the cross-sectional structure of a flush membrane in an embodiment of the present invention; Figure 4 It is a schematic diagram of the process of a method for preparing a flush membrane core according to an embodiment of the present invention.

[0023] Description of reference numerals: 1-steel base; 2-flush membrane; 21-transition layer; 22-insulating layer; 23-composite strain layer: 231-first strain layer, 232-second strain layer, 233-third strain layer, 234-fourth strain layer; 24-protective layer; 25-pad.

[0024] The purpose, features and advantages of this figure will be further described in conjunction with the embodiments with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described and illustrated in conjunction with the embodiments below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0026] Obviously, the following descriptions are only some examples or embodiments of the present invention, and for those of ordinary skill in the art, the present invention can also be applied to other similar scenarios without creative work. In addition, it can also be understood that although the efforts made in such a development process may be complex and lengthy, for those of ordinary skill in the art related to the contents disclosed in the present invention, some changes in design, manufacturing or production based on the technical contents disclosed in the present invention are just conventional technical means, and should not be understood as the contents disclosed in the present invention being insufficient.

[0027] However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially the same structures may be omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present invention and is not intended to limit the subject matter described in the claims.

[0028] If not otherwise specified, all embodiments and optional embodiments of the present invention may be combined with each other to form a new technical solution, and all technical features and optional technical features of the present invention may be combined with each other to form a new technical solution.

[0029] The following is a detailed description of a flush membrane core, a preparation method and application thereof, and a pressure transmitter according to an embodiment of the present invention.

[0030] A first aspect of an embodiment of the present invention provides a flush membrane core, such as Figure 1 As shown, it includes a steel base 1 and a flush membrane 2 arranged on the surface of the steel base; Wherein, the flush membrane 2 includes a composite strain layer 23; Please refer to Figure 2 The composite strain layer 23 includes a first strain layer 231, a second strain layer 232, a third strain layer 233 and a fourth strain layer 234 stacked in sequence; The material of the first strained layer 231 includes SiGeSnN; The material of the second strained layer 232 includes SiGeSnNiN; The material of the third strained layer 233 includes SiGeSnNiCrInN; The material of the fourth strained layer 234 includes SiGeNiCrInGaN.

[0031] The flush film core provided by the embodiment of the present invention has a composite strain layer including four strain layers (a first strain layer, a second strain layer, a third strain layer and a fourth strain layer). Among the four strain layers, in the adjacent first strain layer and the second strain layer, the second strain layer contains all the elements of the first strain layer, and only contains Ni additionally; in the adjacent second strain layer and the third strain layer, the third strain layer contains all the elements of the second strain layer, and only contains Cr and In additionally; in the adjacent third strain layer and the fourth strain layer, the fourth strain layer contains the elements Si, Ge, Ni, Cr, In and N of the third strain layer, and the only difference is that the third strain layer contains Sn and the fourth strain layer contains Ga, and the chemical properties of Sn and Ga are similar; therefore, the element type difference between each layer in the four strain layers of the composite strain layer is small, so that the bonding strength between the adjacent two layers is high, thereby improving the stability of the composite strain layer. Furthermore, the first strain layer, the second strain layer, the third strain layer and the fourth strain layer cooperate with each other to sense pressure from all directions, thereby improving the strain sensitivity of the flush film core. Moreover, in the composite strained layer, N in each strained layer forms silicon nitride and gallium nitride with metal silicon and gallium respectively. Silicon nitride and gallium nitride have high corrosion resistance, high sensitivity and high stability in high temperature or corrosive environment, etc., so that the measurement results are highly accurate.

[0032] In some embodiments, the material of the steel base is 17-4PH stainless steel.

[0033] In some embodiments, please refer to Figure 3 , the flush film 2 further includes a transition layer 21, an insulating layer 22, a protective layer 24 and a pad 25; The transition layer 21, the insulating layer 22, the composite strain layer 23 and the pad 25 are stacked in sequence longitudinally; The protection layer 24 is disposed on the surfaces of the transition layer 21 , the insulating layer 22 and the composite strain layer 23 .

[0034] In this case, the transition layer can improve the bonding between the steel base and the flush membrane, making the flush membrane less likely to fall off and relieving stress; the insulating layer can provide electrical insulation and improve signal quality; the protective layer can protect the composite strain layer and prevent the composite strain layer from reducing sensitivity or even becoming insensitive due to oxidation.

[0035] In some embodiments, the material of the transition layer is 17-4PH stainless steel oxide.

[0036] In some embodiments, the thickness of the transition layer is 190 nm to 250 nm.

[0037] In some embodiments, the material of the insulating layer includes silicon nitride. In some embodiments, the thickness of the insulating layer is 5 μm to 8 μm. In this case, silicon nitride can still maintain good insulation performance at high temperatures and is suitable for high temperature and high corrosion environments.

[0038] In some embodiments, the material of the first strained layer includes the following elements in atomic percentage: Si: 28%~32%, Ge: 25%~31%, Sn: 30%~35%, N: 5%~10%.

[0039] In some embodiments, the thickness of the first strained layer is 80 nm-100 nm.

[0040] In some embodiments, the material of the second strained layer includes the following elements in atomic percentage: Si: 27%~35%, Ge: 28%~37%, Sn: 18%~25%, Ni: 15%~22%, N: 3%~8%.

[0041] In some embodiments, the thickness of the second strained layer is 90 nm-120 nm.

[0042] In some embodiments, the material of the third strained layer includes the following elements in atomic percentage: Si: 19%~25%, Ge: 21%~28%, Sn: 23%~29%, Ni: 17%~21%, Cr: 8%~14%, In: 3%~8%, N: 1%~2%.

[0043] In some embodiments, the thickness of the third strained layer is 110 nm-150 nm.

[0044] In some embodiments, the material of the fourth strained layer includes the following elements in atomic percentage: Si: 23%~28%, Ge: 13%~25%, Ni: 15%~25%, Cr: 18%~21%, In: 5%~10%, Ga: 5%~10%, N: 2%~5%.

[0045] In some embodiments, the thickness of the fourth strained layer is 110 nm-150 nm.

[0046] In some embodiments, the material of the protective layer includes at least one of silicon nitride, aluminum oxide, and silicon oxide.

[0047] In some embodiments, the thickness of the protection layer on the surface of the composite strain layer is 500 nm to 700 nm.

[0048] In some embodiments, the material of the pad is gold or silver.

[0049] In some embodiments, the thickness of the pad is 600nm~800nm.

[0050] A second aspect of the present invention provides a method for preparing a flush membrane core, such as Figure 4 As shown, the following steps are included: S10. Prepare a transition layer, an insulating layer and a composite strain layer on the surface of the steel substrate respectively.

[0051] S20. Fixing a pad on the composite strain layer.

[0052] S30. Preparing a protective layer on the remaining portions of the surfaces of the transition layer, the insulating layer and the composite strained layer.

[0053] In some embodiments, in the above step S10, the step of preparing the transition layer includes: S101. Electrochemical oxidation / heat treatment / mechanical oxidation / plasma oxidation are used to oxidize the steel base surface to form a transition layer. In this case, directly oxidizing the steel base surface to form a transition layer can improve the bonding between the steel base and the flush film, making the insulating layer and the composite strain layer less likely to fall off. It should be noted that the position and area of ​​the steel base surface oxidation are determined by the set position and area of ​​the flush film, and it is not necessary to oxidize the entire surface; electrochemical oxidation / heat treatment / mechanical oxidation / plasma oxidation are all conventional technical means in the field, and the oxidation conditions can be adjusted according to actual needs, and no special instructions are required in the embodiments of the invention.

[0054] In some embodiments, in the above step S10, preparing the insulating layer includes the following steps: Silicon nitride is deposited on the surface of the transition layer by chemical vapor deposition to form an insulating layer.

[0055] In some specific embodiments, the chemical vapor deposition method is specifically low pressure chemical vapor deposition (LPCVD) or plasma enhanced chemical vapor deposition (PECVD).

[0056] In some specific embodiments, depositing silicon nitride by low pressure chemical vapor deposition (LPCVD) includes the following steps: A silicon nitride precursor gas is deposited at a pressure of 600Pa-800Pa and a temperature of 700°C-800°C to obtain a silicon nitride insulating layer; wherein the silicon nitride precursor gas is silane (SiH4) and ammonia (NH3). It should be noted that low-pressure chemical vapor deposition is an existing technology, and parameters such as the volume ratio of silane (SiH4) and ammonia (NH3) in the silicon nitride precursor and the flow rate of the precursor can be adjusted as needed, and no special limitation is required in the embodiments of the present invention.

[0057] In some specific embodiments, depositing silicon nitride by plasma enhanced chemical vapor deposition (PECVD) includes the following steps: A silicon nitride precursor gas is deposited at a microwave frequency of 2450 MHz to 3000 MHz and a temperature of 200°C to 400°C to obtain a silicon nitride insulating layer; wherein the silicon nitride precursor gas is silane (SiH4) and ammonia (NH3). It should be noted that low-pressure chemical vapor deposition is an existing technology, and parameters such as the volume ratio of silane (SiH4) and ammonia (NH3) in the silicon nitride precursor, the flow rate of the precursor, and the pressure of the deposition chamber can be adjusted as needed, and no special limitation is required in the embodiments of the present invention.

[0058] In some embodiments, in the above step S10, the step of preparing the composite strained layer includes: The first strain layer, the second strain layer, the third strain layer and the fourth strain layer are sequentially deposited on the surface of the insulating layer away from the transition layer by magnetron sputtering coating method. It should be noted that the sputtering conditions of the magnetron sputtering coating method can be adjusted as needed, and there is no need to make special restrictions in the embodiment of the present invention. However, as an example, the sputtering power when depositing the first strain layer can be 300W~400W, and the substrate temperature can be 600℃~800℃; the sputtering power when depositing the second strain layer can be 350W~450W, and the substrate temperature can be 500℃~550℃; the sputtering power when depositing the third strain layer can be 150W~250W, and the substrate temperature can be 230℃~350℃; the sputtering power when depositing the fourth strain layer can be 130W~220W, and the substrate temperature can be 210℃~320℃.

[0059] In some embodiments, in the above step S30, preparing the protective layer includes the following steps: The protective layer is deposited on the transition layer, the insulating layer, and the composite strain layer and the remaining surface away from the steel substrate by magnetron sputtering coating method. It should be noted that the sputtering conditions of the magnetron sputtering coating method can be adjusted as needed, and there is no need to make special restrictions in the embodiments of the present invention, but as an example, the sputtering power of the deposition can be 450W~600W, and the substrate temperature can be 600℃~800℃.

[0060] A third aspect of an embodiment of the present invention provides a pressure transmitter, comprising the flush membrane core provided by the above-mentioned embodiment of the present invention.

[0061] A fourth aspect of the embodiments of the present invention provides an application of the flush membrane core provided by the above-mentioned embodiments of the present invention in the field of strained materials.

[0062] The following is further described in conjunction with specific embodiments.

[0063] Example 1 Embodiment 1 provides a flush membrane core body, which is composed of a 17-4PH stainless steel base and a flush membrane on the steel base; The flush membrane is composed of a transition layer, an insulating layer, a composite strain layer, a protective layer and a pad. The steel base, the transition layer, the insulating layer, the composite strain layer and the pad are stacked in sequence longitudinally, and the protective layer is arranged on the surfaces of the transition layer, the insulating layer and the composite strain layer. The material of the transition layer is 17-4PH stainless steel oxide and the thickness is 235nm.

[0064] The insulating layer is made of silicon nitride and has a thickness of 7.1 μm.

[0065] The material of the protective layer is aluminum oxide, and the thickness on the surface of the composite strain layer is 633 nm.

[0066] The pad material is gold pad with a thickness of 700nm.

[0067] The composite strain layer consists of the following materials: A first strained layer, a second strained layer, a third strained layer and a fourth strained layer are stacked in sequence, wherein the first strained layer is bonded to the insulating layer; The material of the first strained layer is: Si: 31%, Ge: 29%, Sn: 32%, N: 8%, and the thickness is 97nm; The material of the second strained layer is: Si: 28%, Ge: 30%, Sn: 19%, Ni: 18%, N: 5%, and the thickness is 108nm; The materials of the third strained layer are: Si: 20%, Ge: 23%, Sn: 25%, Ni: 19%, Cr: 9%, In: 3%, N: 1%, and the thickness is 128nm; The material of the fourth strained layer is: Si: 28%, Ge: 20%, Ni: 17%, Cr: 18%, In: 5%, Ga: 10%, N: 2%, and the thickness is 138 nm.

[0068] This embodiment also provides a method for preparing a flush membrane core, the steps are as follows: S1. The steel substrate surface is oxidized by plasma oxidation to obtain a transition layer.

[0069] S2. Deposit silicon nitride precursor gas at a pressure of 682 Pa and a temperature of 769° C. to obtain a silicon nitride insulating layer; wherein the silicon nitride precursor gas is silane (SiH4) and ammonia (NH3).

[0070] S3. The first strain layer (sputtering power is 394 W, substrate temperature is 700°C), the second strain layer (sputtering power is 400 W, substrate temperature is 500°C), the third strain layer (sputtering power is 238 W, substrate temperature is 320°C) and the fourth strain layer (sputtering power is 150 W, substrate temperature is 290°C) are deposited in sequence on the surface of the insulating layer away from the transition layer by magnetron sputtering coating method.

[0071] S4. A protective layer was deposited on the transition layer, the insulating layer, the composite strain layer and the remaining part away from the steel substrate by magnetron sputtering coating method, with a sputtering power of 550 W and a substrate temperature of 710°C.

[0072] Example 2 Embodiment 2 provides a flush membrane core body, which is composed of a 17-4PH stainless steel base and a flush membrane on the steel base; The flush membrane is composed of a transition layer, an insulating layer, a composite strain layer, a protective layer and a pad. The steel base, the transition layer, the insulating layer, the composite strain layer and the pad are stacked in sequence longitudinally, and the protective layer is arranged on the surfaces of the transition layer, the insulating layer and the composite strain layer. The material of the transition layer is 17-4PH stainless steel oxide and the thickness is 190nm.

[0073] The insulating layer is made of silicon nitride and has a thickness of 8 μm.

[0074] The material of the protective layer is aluminum oxide, and the thickness on the surface of the composite strain layer is 699 nm.

[0075] The pad material is gold pad with a thickness of 800nm.

[0076] The composite strain layer consists of the following materials: A first strained layer, a second strained layer, a third strained layer and a fourth strained layer are stacked in sequence, wherein the first strained layer is bonded to the insulating layer; The material of the first strained layer is: Si: 29%, Ge: 31%, Sn: 30%, N: 10%, and the thickness is 100nm; The material of the second strained layer is: Si: 35%, Ge: 29%, Sn: 18%, Ni: 15%, N: 3%, and the thickness is 120nm; The materials of the third strained layer are: Si: 25%, Ge: 21%, Sn: 23%, Ni: 17%, Cr: 8%, In: 4%, N: 2%, and the thickness is 150nm; The material of the fourth strained layer is: Si: 25%, Ge: 25%, Ni: 15%, Cr: 19%, In: 5%, Ga: 9%, N: 2%, and the thickness is 150 nm.

[0077] This embodiment also provides a method for preparing a flush membrane core, and the steps are the same as those in Embodiment 1.

[0078] Example 3 Embodiment 3 provides a flush membrane core body, which is composed of a 17-4PH stainless steel base and a flush membrane on the steel base; The flush membrane is composed of a transition layer, an insulating layer, a composite strain layer, a protective layer and a pad. The steel base, the transition layer, the insulating layer, the composite strain layer and the pad are stacked in sequence longitudinally, and the protective layer is arranged on the surfaces of the transition layer, the insulating layer and the composite strain layer. The material of the transition layer is 17-4PH stainless steel oxide and has a thickness of 250nm.

[0079] The insulating layer is made of silicon nitride and has a thickness of 5 μm.

[0080] The material of the protective layer is aluminum oxide, and the thickness on the surface of the composite strain layer is 500 nm.

[0081] The pad material is gold pad with a thickness of 600nm.

[0082] The composite strain layer consists of the following materials: A first strained layer, a second strained layer, a third strained layer and a fourth strained layer are stacked in sequence, wherein the first strained layer is bonded to the insulating layer; The material of the first strained layer is: Si: 28%, Ge: 27%, Sn: 35%, N: 10%, and the thickness is 80nm; The material of the second strained layer is: Si: 27%, Ge: 28%, Sn: 20%, Ni: 19%, N: 6%, and the thickness is 90nm; The materials of the third strained layer are: Si: 19%, Ge: 21%, Sn: 23%, Ni: 18%, Cr: 13%, In: 5%, N: 1%, and the thickness is 110nm; The material of the fourth strained layer is: Si: 23%, Ge: 17%, Ni: 25%, Cr: 21%, In: 56%, Ga: 5%, N: 3%, and the thickness is 110 nm.

[0083] This embodiment also provides a method for preparing a flush membrane core, and the steps are the same as those in Embodiment 1.

[0084] Comparative Example 1 Comparative Example 1 provides a flush membrane core, the structure of which is basically the same as that of Example 1, except that: There is only one strained layer, the material is Si: 20%, Ge: 23%, Sn: 25%, Ni: 19%, Cr: 9%, In: 3%, N: 1%, and the thickness is 471nm.

[0085] Comparative Example 2 Comparative Example 2 provides a flush membrane core, the structure of which is basically the same as that of Example 1, except that: There is no transition layer; the material of the insulating layer is silicon nitride and the thickness is 7.34μm.

[0086] Comparative Example 3 Comparative Example 3 provides a flush membrane core, the structure of which is basically the same as that of Example 1, except that: The stacking order of the first strained layer, the second strained layer, the third strained layer and the fourth strained layer in the composite strained layer is: The fourth strained layer, the third strained layer, the second strained layer and the first strained layer are sequentially stacked, and the fourth strained layer is in contact with the insulating layer.

[0087] Accordingly, Comparative Example 3 also proposes a method for preparing a flush membrane core, and the steps are basically the same as those of Example 1, except that: In step S3, a fourth strained layer, a third strained layer, a second strained layer and a first strained layer are sequentially deposited on a surface of the insulating layer away from the transition layer by a magnetron sputtering coating method.

[0088] Comparative Example 4 Comparative Example 4 provides a flush membrane core, the structure of which is basically the same as that of Example 1, except that: The composite strain layer does not contain a third strain layer.

[0089] Accordingly, Comparative Example 4 also proposes a method for preparing a flush membrane core, and the steps are basically the same as those of Example 1, except that: In step S3, a first strained layer, a second strained layer and a fourth strained layer are sequentially deposited on a surface of the insulating layer away from the transition layer by a magnetron sputtering coating method.

[0090] Comparative Example 5 Comparative Example 5 provides a flush membrane core, the structure of which is basically the same as that of Example 1, except that: The composite strained layer does not contain a fourth strained layer.

[0091] Accordingly, Comparative Example 5 also proposes a method for preparing a flush membrane core, and the steps are basically the same as those of Example 1, except that: In step S3, a first strained layer, a second strained layer and a third strained layer are sequentially deposited on a surface of the insulating layer away from the transition layer by a magnetron sputtering coating method.

[0092] In order to verify the advancement of the flush membrane core and the preparation method of the embodiment of the present invention, the flush membrane in the flush membrane core provided by the embodiment and the comparative example was subjected to a corrosion resistance test according to GB / T10125-201; and the flush membrane core provided by the embodiment and the comparative example was made into a pressure transmitter and then subjected to an overload capacity test. The results are shown in Table 1 below.

[0093] Overload test method: Use fatigue impact equipment to perform fatigue impact test on the manufactured pressure products in the range of 200%FS~500%FS (first filter out the wide range at 100%FS; then filter out the final result at 10%), the test conditions are 1W times, 24 times / min; after fatigue is completed, the product is calibrated in accordance with the verification procedures of JJG 882-2019 "Pressure Transmitter", and the product must meet the performance requirements.

[0094] .

[0095] From the data in Table 1 above, at least the following conclusions can be drawn: (1) It can be seen from the corrosion rates of the embodiments and the comparative examples that in the composite strained layer of the flush film core provided by the embodiment of the present invention, when the protective layer remains unchanged, the N in each strained layer forms silicon nitride and gallium nitride with metal silicon or gallium in the embodiment, and the silicon nitride and gallium nitride have high corrosion resistance, and the corrosion resistance of the four-layer strained layer is better than that of the three-layer or less strained layer, so that the flush film core provided by the embodiment of the present invention has high sensitivity and high stability in high temperature or corrosive environment, and thus the measurement result has high accuracy.

[0096] (2) It can be seen from the overload capacity data of the embodiment and the comparative example that the pressure transmitter with a flush membrane core provided in the embodiment of the present invention has a very high overload capacity, which enables it to maintain stable performance in a harsh working environment and provide accurate pressure data.

[0097] It should be noted that the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, without departing from the scope of the main purpose of the present invention, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A flush membrane core, comprising a steel base and a flush membrane; characterized in that: The flush membrane includes a composite strain layer; The composite strain layer comprises a first strain layer, a second strain layer, a third strain layer and a fourth strain layer stacked in sequence; The material of the first strained layer includes SiGeSnN; The material of the second strained layer includes SiGeSnNiN; The material of the third strained layer includes SiGeSnNiCrInN; The material of the fourth strained layer includes SiGeNiCrInGaN.

2. The flush membrane core according to claim 1, characterized in that: The material of the first strained layer includes the following elements in atomic percentage: Si: 28%~32%, Ge: 25%~31%, Sn: 30%~35%, N: 5%~10%.

3. The flush membrane core according to claim 1, characterized in that: The material of the second strained layer includes the following elements in atomic percentage: Si: 27%~35%, Ge: 28%~37%, Sn: 18%~25%, Ni: 15%~22%, N: 3%~8%.

4. The flush membrane core according to claim 1, characterized in that: The material of the third strained layer includes the following elements in atomic percentage: Si: 19%~25%, Ge: 21%~28%, Sn: 23%~29%, Ni: 17%~21%, Cr: 8%~14%, In: 3%~8%, N: 1%~2%.

5. The flush membrane core according to any one of claims 1 to 4, characterized in that: The material of the fourth strained layer includes the following elements in atomic percentage: Si: 23%~28%, Ge: 13%~25%, Ni: 15%~25%, Cr: 18%~21%, In: 5%~10%, Ga: 5%~10%, N: 2%~5%.

6. The flush membrane core according to claim 5, characterized in that: The flush film also includes a transition layer, an insulating layer, a protective layer and a pad; The steel base, the transition layer, the insulating layer, the composite strain layer and the pad are stacked in sequence longitudinally; The protective layer is arranged on the surfaces of the transition layer, the insulating layer and the composite strain layer.

7. The flush membrane core according to claim 6, characterized in that: The thickness of the first strained layer is 80nm-100nm; The thickness of the second strained layer is 90nm-120nm; The thickness of the third strain layer is 110nm-150nm; The thickness of the fourth strain layer is 110nm-150nm.

8. A method for preparing a flush membrane core according to any one of claims 1 to 7, characterized in that: The steps include: Prepare a transition layer, an insulating layer and a composite strain layer on the surface of the steel base respectively; fixing a pad on the composite strain layer; The protective layer is formed on the remaining parts of the surfaces of the transition layer, the insulating layer and the composite strained layer.

9. A pressure transmitter, characterized in that: It comprises a flush membrane core as described in any one of claims 1 to 7.

10. Use of the flush membrane core according to any one of claims 1 to 7 in the field of strain materials.

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